redis is amazing <3

gistfile1.txt

# 100mil 'entities'
# need to be able to check from a random subset if 'something' is TRUE or FALSE

# set booleans in a redis bitmap where the ID for the entities are the offset 

$ redis-cli

> SETBIT mybitmap 100000000 1       # 8ms
> SETBIT mybitmap  99999999 1       # 2ms
> SETBIT mybitmap  10000000 1       # 2ms, etc
> SETBIT mybitmap   1000000 1
> SETBIT mybitmap    100000 1
> SETBIT mybitmap     10000 1
> SETBIT mybitmap      1000 1
> SETBIT mybitmap       100 1
> SETBIT mybitmap        10 1
> SETBIT mybitmap         1 1

# memory used for this bitmap 16MB

> GETBIT mybitmap 99999999         # 2ms
> GETBIT mybitmap 99988889         # 2ms